


Lack of Instinct

by Caelum (zanarkand)



Series: Cor and Prompto headcanon fics [2]
Category: Final Fantasy XV
Genre: Alternate Universe, Angst, Backstory, Fan theories, Gen, Headcanon, Spoilers, all the feels, pre-game, thanks Prompto DLC
Language: English
Status: Completed
Published: 2017-03-03
Updated: 2017-10-13
Packaged: 2018-09-28 01:05:03
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 8,617
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10060766
Author URL: https://archiveofourown.org/users/zanarkand/pseuds/Caelum
Summary: Cor has no idea how to do this parenting thing.[This follows directly after the last section ofWhat Lies Below.]





	1. The First Day

**Author's Note:**

> Okay, fine, guys, make a liar out of me :P I said I didn't have any more plans to expand on my headcanon in _What Lies Below_ , and yet here I am. The response was so much more positive than I expected, and I really adore this headcanon, so I couldn't leave it alone. I don't know where I'm going with any of this, though, so I'll probably just write random fics about it as they come to me. I've turned it into a series so it'll be easier to keep them all together.

The first day dawns overcast and dismal. Instead of his alarm, Cor's woken at five in the morning by the shrill sound of a baby's cries. He takes a groggy moment to wonder when his neighbours had a kid, before he realises the sound is way too close to be coming from the next door apartment. He sits up, and stares blankly down at the small child in his bed next to him, sobbing his little heart out. It doesn't take long for it to come back to him. The knock, Sophia, his promise.

Prompto. 

He sighs, scrubbing a hand over tired eyes, and wonders what the hell he's supposed to do with a baby. He's not good with children, doesn't know how to act around them, or take care of them. He's never planned to have children of his own, despite his mother's constant nagging for him to settle down soon and give her grandchildren. She can't understand that he's married to his job, and he _likes_ it that way. He enjoys the company of both men and women from time to time, but a relationship is an entanglement he has no interest in. 

Prompto's wails get louder, and Cor groans, getting out of bed and picking the child up. He thinks back to the times he'd seen Regis with baby Noctis over the past year, and after a moment awkwardly begins to rock Prompto. "It's okay," he tells the child, trying to ignore how stupid he currently feels. "Don't cry." 

Gods, but he is terrible at this. Still, after a bit Prompto's cries do taper off, and eventually he's nestled quietly in Cor's arms, looking up at him with watery eyes. The child's eyes are a brilliant blue. Yet another way he looks just like his mother. He feels a stab of sorrow for his old childhood friend. 

Prompto shifts in Cor's arms, and resolutely he shoves all thoughts of Sophia away. There will be time to mourn later. Right now he has a one year old to take care of. 

He deals with work first, bypassing the usual order of things to call Regis directly. The king will know he's lying, but that's precisely why Cor calls him. He never lies, and for him to be doing so to the king directly means Regis will know it's something serious, and hopefully not question him too deeply. 

"Food poisoning," Regis says, and Cor can just imagine the raised eyebrows that go along with the sense of befuddlement in his tone. 

"Yes, Your Majesty," Cor tells him. "It's bad. I may be out for a few days." 

There's a silence, long enough that Cor begins to sweat, wondering if he'd miscalculated, but finally, _finally_ Regis responds. "Very well," he says. "I'll let the Crownsguard know. Keep me updated." 

"Thank you, Your Majesty," he says, and waits for Regis to end the call on his end before he lowers the phone. He breaths out in relief, and looks at the child now sitting on his sofa. "Well, Prompto, that's one issue dealt with," he says, and the boy gives him a wide grin, letting Cor catch sight of the single tooth he has in the upper right side of his mouth. The sight tugs at Cor's heartstrings, and he thinks again of raising the child for himself. 

He knows he can't, however. He doesn't have the time, and though he trusts Regis enough to tell him at least some of the truth, he doesn't trust anyone else, and even Regis would be hard-pressed to deal with the cry for blood that would emerge if it got out that Niflheim turned babies into MTs, and there was one in Insomnia's midst. 

He sinks down into the sofa, feeling the beginnings of a headache coming on, and tries to figure out what to do next. Prompto crawls over to him, climbing in his lap, reaching out chubby arms to pat at Cor's chest, babbling happily. He doesn't seem to be able to talk yet, and Cor's not sure if that's concerning. Prince Noctis had said his first word at nine months, a fact that Regis made sure everyone in the Citadel knew. 

He wishes he could ask for Regis' help now. Regis has taken to parenthood with amazing ease, knowing instinctively how to handle Noctis' every cry and mood change. He'd probably know just how to deal with Prompto. Unfortunately, Cor knows he can't risk it, not right now. He'll have to figure this out alone. 

He's not even sure what babies need. Food, obviously, and probably diapers, maybe a bottle still...? Definitely clothes, given that he's dressed in ones that are little more than rags. Probably some kind of toy to keep him occupied. A trip to a department store is definitely going to be needed, but he's uncertain how to manage that. He can't leave the kid alone in his apartment while he goes out, but he risks being spotted by people he knows if he goes to the store with the kid in tow. 

Although... Insomnia's a big city. If he goes to a store in an area he doesn't frequent, he'll probably be fine. "How about it, Prompto?" he asks, suddenly decided. "You wanna take a trip with me?" He reaches out, placing a gentle hand on top of the baby's head, briefly stroking his fingers through the soft, fine hair. Prompto giggles and looks up at Cor's face, his eyes shining. Cor firmly tells himself he can't get attached. He can't keep this kid. 

* * *

The first obstacle he runs into is that he doesn't have a car seat. He stands there for a long moment of indecision, Prompto wriggling restlessly in his arms. The car's a Crownsguard issue, one of the latest, and it's pretty sturdy, made to withstand a lot of damage and protect its passengers, but he's pretty sure the makers never factored in one-year olds without car seats. 

Finally, realising he has little choice, he straps Prompto into the back seat as tightly as possible, adjacent to him so he can glance back and keep an eye on the kid from time to time. He'll just drive slow. 

The second obstacle he runs into is at the store—he has no idea what to get. He and Prompto had managed to make it across town without any mishaps, and Cor had spotted a store that seemed geared towards selling just baby things, but now that they're both in it and surrounded by everything a baby could possibly need, he feels at a loss. He stands uncertainly in the middle of the aisles, constantly looking around in indecision and absently rocking Prompto from time to time, until finally an employee takes pity. 

"Can I help you with anything, sir?" she asks politely as she approaches him. 

"Ah—" he looks at her. She's young, probably about his age, and has a warm, friendly smile on her face. It puts him at ease, and makes him feel a little less embarrassed to admit he's totally clueless. "Yes," he decides, nodding at her. "This boy came into my care last night, and I'm not sure what to get him." 

She looks at Prompto, who gives her a toothy grin, and smiles. "How adorable!" she says. "How old is he?" 

"One. His name is Prompto," he adds. 

"Well, what kinds of things are you looking to get Prompto?" she asks him. 

"Everything. He was given to me with only the clothes he's wearing now." 

She arches her eyebrows in surprise. "Well," she says, looking towards the front of the store. "The first thing you're going to need is a shopping cart." 

Three hours later, he staggers towards the row of registers, feeling a little shell-shocked, the young woman who had helped him following behind him, pushing his cart. He had _no idea_ babies needed that many things. Prompto's fallen asleep in his arms, and Cor's just glad he seems to be a quiet baby—Prince Noctis is a fussy thing, and Cor doesn't know if he could handle it if Prompto turned out to be the same way. 

When the total comes, it makes him wince, but he pays it without a second thought. Prompto needs these things, and Cor thinks it'll give the boy a better chance of being adopted if the family doesn't have to immediately spend a ton of money on him. At the car, he straps Prompto into the new car seat he's just bought, and then settles in for the thirty minute drive back to his apartment. 

* * *

Prompto's wailing—screaming, really—at the top of his lungs, and Cor has no idea what to do. He's fed the kid, bathed him, gotten him in clean clothes and a new diaper, given him toys to play with, rocked him... none of it's working. Prompto's been crying and screaming for the past twenty minutes, and if he weren't feeling so frazzled he'd be impressed by the set of lungs the child has on him. He's sure that if he doesn't get the boy settled down soon, some of his neighbours are going to be over here complaining. 

A knock sounds at the door just then, and Cor sighs. Speak of daemons, and they show up. Leaving Prompto to his sobs, he goes over to get the door, hoping he can placate the neighbours enough to leave. Or possibly intimidate them with his position in the Crownsguard until they flee in terror, whichever works. 

But when he pulls open the door, it's not a disgruntled neighbour standing there. It's the king himself, craning his neck curiously to look past Cor at the playpen that's now in the middle of Cor's small living room. 

"Y-your Majesty," Cor says, flustered. "What are you doing here?" He winces at how accusing that sounds, but it's unusual for the king to leave the Citadel outside of official business, much less show up on Cor's doorstep. 

"Food poisoning, Cor?" Regis asks, mild amusement lacing his tone. 

"Ah, perhaps not—" Belatedly, he realises he's leaving the king to stand outside in the chill November air, and hastily steps aside, sweeping an arm to invite Regis in. 

Regis takes the invitation, stepping in and heading straight for the playpen, where Prompto's still crying noisily. Cor shuts the door behind the king and watches him, making no move to step in. Regis spends a few minutes soothing the boy, and though Prompto's sobs don't stop altogether, they do lessen into something quieter and less desperate sounding, easing the ache in Cor's head a little. 

"He's teething," Regis says, looking up at Cor. "You need to get him a teething ring." 

"I have one, somewhere..." He digs through the bags of stuff he'd dumped on the sofa to deal with later, finally finding the small plastic ring the young lady had placed in his cart. He stares at it blankly for a moment, then hands it over to Regis, clueless. 

Regis extracts it from the packaging, and then gives it to Prompto, who immediately sticks it between his lips, mouthing at it, his sobs at last tapering off. Cor sighs in relief, shifting the bags to the floor so he can sink down into the cushions. "How did you know?" he asks curiously. 

Regis smiles at him, coming over to take a seat next to Cor, settling Prompto in his lap. "The tooth's beginning to poke through." 

"Oh." Cor closes his eyes, feeling weary. He hadn't noticed at all. It reminds him how bad he is at this parenting thing, reinforcing why he absolutely can't keep the boy. He feels a warm weight in his lap then, and opens his eyes again to see Prompto's crawled onto him, still gnawing away at the soft ring in his mouth. He sighs, loosely wrapping his arms around the boy to keep him from falling or moving around too much. 

"I came to see what was so important it would keep you from work for a few days," Regis says quietly, his voice serious now. "This is certainly not something I expected to find." 

"I can explain." 

"By all means." 

Yet now that he's offered, Cor's not sure how to. He absolutely can't explain about the barcode, and what he suspects it means, but even telling Regis that Prompto is from Niflheim is risky. And if he mentions Sophia at all, Regis is sure to figure that much out—he's never spoke of it, but Cor knows he's always been aware of her flight to Niflheim, and how much it hurt Cor to lose his childhood friend. "His name's Prompto," he finally says. That much is probably safe. 

Regis waits patiently, but when it's clear that no more is forthcoming, he speaks. "He's not yours," he says, with just a touch of uncertainty. 

Cor shakes his head, looking down at the small child in his lap. He has no idea who the boy's father is. Sophia had said so little, and he'd been too shocked by the events to really try and question her on anything before she'd left. "I don't know who the father is," he says honestly. 

"And the mother?" 

Cor looks back up at the king, hesitating. "I can't say." 

The king's silent a moment, studying the boy. Prompto's cuddled up comfortably against Cor's stomach, a bit of drool trailing down his chin as he chews on the teething ring. His blue eyes are bright with wonderment as he stares back at the king, and the freckles across his nose stand out starkly in contrast to his pale skin. "He reminds me of a young Sophia," Regis muses quietly. Cor says nothing, though he knows his silence says just as much as words could. "How old is he?" 

"One. And a month, give or take." There'd been a scrap of paper wrapped up in the cloths with him, that Cor had found last night. Sophia's handwriting had filled it. _Prompto_ , had been written. _M.E. 735. October 25. Gralea, Niflheim._ He can only assume the date is Prompto's birthday. 

"What do you plan to do with him?" 

"I..." Unconsciously, he reaches out, running gentle fingers through Prompto's soft hair. He's not really aware of the movement, too focused on his conversation with Regis. "I'm hoping to find a family to adopt him," he says reluctantly. It's so tempting, to say he'll keep the boy and raise him. Cor doesn't even know _why_ , really. He could blame it on the child being Sophia's, but he doesn't think that's it. There's just something about Prompto—looking at him raises all kinds of protective emotions and paternal instincts Cor's never before had, and it's confusing, and terrifying, but he's so drawn to this small boy that the thought of giving him up is even more terrifying than keeping him. 

Regis watches him for a bit, his green eyes taking everything in. "You wish to keep him." 

"I cannot," he replies immediately. "It wouldn't be fair to him." 

"You would hardly be the first member of the Crownsguard to be a parent," Regis points out, but Cor shakes his head. 

"He deserves a family that would have time for him, and would take good care of him." 

The king sighs at his words, but doesn't try to convince him otherwise. "Am I to assume you wish the time off to find him a family, then?" 

"Yes, Your Majesty," he says, slipping back into formality at the business-like tone suddenly present in the king's words. 

Regis waves it away. "No need for that," he says absently. "How soon do you think you can find him one?" 

"I'm not sure," Cor admits slowly. He thinks about it. "I have some idea of where to start, but I'll need to be discreet, and go through some people... A week, perhaps? I know that's asking for a lot, but—" 

He's interrupted by Regis holding up a hand. "The Crownsguard can survive without you for a week," he says, his eyes sparkling with amusement. A hint of a grin tugs at his mouth. "Clarus can find someone to cover for you, if necessary. They won't fall apart in your absence, Cor, I assure you." 

Cor gives him a disgruntled look, choosing not to dignify that with a response. 

Regis laughs outright, then, and stands. He reaches out to tousle Prompto's hair, smiling at the baby. "I shall take my leave then," he says. "Find him a good family, Cor." 

"I'll do my best," Cor tells him quietly, and stands as well, cradling Prompto in his arms as he sees the king to the door. 

"Call me if you need any help. With any of it," Regis says as he stands on Cor's doorstep, giving him a firm look. 

"I will," Cor murmurs, shifting Prompto to one arm as he raises the other in a farewell. He shuts the door behind Regis, and hopes he won't come to regret the king finding out.

**Notes for the Chapter:**

> I have no idea if there will be more to this particular fic. I make no promises.
> 
> I also can't stop listening to Apocalypsis Noctis and Apocalypsis Aquarius on repeat. So awesome.


	2. The Second Day

**Notes for the Chapter:**

> I haven't forgotten about this series... I just have a lot of different fics going on right now. And real life is a struggle... everything is an effort. But here's a small offering.

The second day dawns bright and sunny, starting off much better than the first. Cor's woken by his alarm at 5:30. After his usual morning routine, he wanders into his living room with a mug of coffee in hand to check on Prompto. The toddler is sleeping soundly in the playpen—the only place for him since Cor hadn't gone as far as buying furniture—and he decides to leave him to sleep. Taking a sip of his coffee, he wanders over to the window and looks absently out. The sun's just starting to rise, lighting up the sky with its brilliant hues. It feels weird to him, to not be going into work right now.

Briefly he entertains the thought of what would happen if he just went in to work anyway, Prompto in tow. The initial reactions of everyone would be highly amusing. Most of the Crownsguard would probably be busy staring while simultaneously trying desperately to look as if they found nothing amiss with their superior showing up to work with a baby. Clarus would likely offer him a babysitter, perhaps the one he used for Gladiolus, and then grill him intensely in private later on. Of course, trying to explain Prompto to him would be a nightmare... 

Behind him, Prompto stirs in the playpen, and Cor sighs. He takes another sip of coffee before setting the mug down on the windowsill and going over to the child. Better to deal with him now, before he fully wakes and starts wailing at the top of his lungs again. So far Prompto is still a mostly quiet baby, but when he decides to cry he makes sure everyone within the surrounding several miles knows it, and Cor would like to spare his eardrums the agony. 

It's still awkward to him, taking care of Prompto—it doesn't come naturally. He'd had to go online yesterday and look up videos on how to change a diaper, and even then it had still taken him way too long to get the whole thing done. He's slightly better at it this morning, but it still feels as if it's taking him twice as long as it should. Thankfully Prompto sits through the process quietly, looking around Cor's bedroom with still sleepy eyes. 

Getting clean clothes on the kid is harder. Prompto's starting to wake up more fully, and is eager to start crawling around and exploring the apartment. He wriggles about, fighting against the pants and shirt Cor has for him. Finally Cor gets them on and steps back to look at him—and only then realises Prompto's shirt is on inside out. He groans, aggravated, but decides to leave it. He's not planning on going anywhere today, and if the need arises he'll fix it then. 

Breakfast is another battle, and after Prompto winds up wearing half of it, Cor gives up, sticking him back in the playpen. Prompto doesn't like this restriction, and immediately begins to wail, banging his chubby little fists against the mesh netting. Cor groans again. After a moment's panicked thought, he switches on the tv, and hurriedly flips through the channels until he manages to find a cartoon playing on one of them. Luckily it's geared towards younger children, and the cheerful singing soon attracts Prompto's attention, quieting his sobs. When Cor is sure Prompto is sufficiently distracted, he retrieves his now cold coffee and settles down onto the sofa to figure out what to do next. 

There's no shortage of families in Insomnia looking to adopt, and Prompto's looks and young age will make him a prime candidate. But Cor doesn't dare risk putting him through the system. That will involve background checks, and questions Cor can't answer. Yet he doesn't want to give Prompto up to the first family that comes along, either. Whoever adopts him will have to be okay with him coming from Niflheim, and the fact that he has a barcode on his wrist, though Cor won't dare tell them his suspicions about just what it means until they've already agreed to adopt him. He'll just have to make it clear that they can't back out. And maybe keep an eye on the child for awhile afterwards, just in case. 

First, however, he's got to find a family to adopt him. He doesn't know of any families personally, given that he doesn't socialise too often. But he seems to recall one of the newer recruits talking about some relatives that had been unsuccessful in conceiving a child of their own, and had been struggling to get through all the paperwork the system required. They might turn out to be unsuitable, but at least they're a place to start. He'll just need to make a few phone calls, and take care in how he words things. 

"What do you say, Prompto?" he says, getting to his feet to go grab his phone off the charger. "You wanna see about finding you a family?" 

Prompto lets himself be distracted from the television long enough to turn around and grin at Cor. He babbles some nonsense happily, clapping his hands together, and Cor can't help but smile at him, though it's tinged with melancholy. He's only known the kid for little more than a day, but gods he does not want to let this child go. 

* * *

Two hours and several phone calls later, Cor wearily plugs his cell back into the charger, feeling a strange emotional mix of hopeful and sad. He's wound up with _three_ families to meet with, along with a couple of favours owed to people in exchange for their silence and help. "Looks like we might be in luck, kid," he tells the boy. "One of these families is probably going to want you." 

Prompto simply blinks at him, eyes slightly glazed over from all the television he's watched. Cor stares back at him, suddenly unsure what to do with the rest of his day. He's not meeting any of the families today, and the remainder of the day looms before him, wide open and empty. Prompto stands, still looking at Cor, and grabs at the side of the playpen, pulling on the netting unhappily. "Uh!" he says, lifting his arms up, and Cor raises surprised eyebrows. It's not quite a word, but it's clearly an attempt at one, and it's encouraging to see the kid try to talk. 

He goes over and picks Prompto up, and the boy immediately snuggles up against his chest happily, a big smile on his face. Cor takes in a breath and tells himself that he's meeting tomorrow with with two families that are interested in adopting Prompto. He has to ignore the ache in his heart he feels every time Prompto's affectionate toward him. It's not as if the kid really has an attachment to _him_ , not specifically. Prompto would probably have latched on to anyone Sophia gave him to, anyone that spent the time to take care of him. 

_But he immediately crawled out of King Regis' lap and into yours yesterday_ , his brain reminds him. He ignores it. It was only because Prompto was more familiar with him. 

_Coward_ , his brain hisses. Well, he's not going to dispute that. 

A chubby fist reaches up and smacks into his face, and Cor winces at the sting. "What was that for?" he asks the kid, but of course he only gets a smile in return. He sighs. "What in the world am I supposed to do with you," he muses. 

Prompto looks at him, scrunching up his face as he starts to fuss. Remembering yesterday, Cor goes into the kitchen, retrieving the teething ring he'd stuck in the fridge, and hands it to the baby, who immediately begins gnawing on it happily, settling down some. Not knowing what else to do, he goes back to the living room and settles down on the sofa, Prompto in his lap. It's not long before his thoughts begin to wander—to Sophia. 

How had she wound up with a child? When they were growing up, she'd always claimed to never want children. Had she changed her mind? Or had it been an accident? Or maybe it had been against her will... she'd certainly seemed to love the boy, though, given the desperate promise she'd extracted from Cor the other night. It had hurt his heart, to see her like that. Even though he'd been so angry at her, he's always hoped that she was doing well in Niflheim, making a decent life for herself, finding happiness. Now he's seen it hasn't been like that for her at all. 

She'd clearly been on the run from Niflheim, for quite some time, and he wonders why, and if anyone would come looking. If they did, would it be for her, or for Prompto? He can't imagine what Niflheim would want with a baby, why—or how—they would turn them into MTs, but that barcode definitely isn't there just for looks, given Sophia's words. And her statement about no longer being human... it could have been an exaggeration, but he has the feeling she'd meant it in a literal sense, though what _that_ means, he's uncertain. 

It's something to start looking into, on the side, once Prompto's adopted and he's back at work. And it might help him in keeping an eye on the boy, if he knows whether there are likely to be people after him or not. Whatever family ends up adopting Prompto, he'll have to make sure they're aware of the potential danger they're placing themselves in. It's going to be tricky, telling the possible families just enough to reel them in without telling them too much to scare them off. They can't back out once they know the truth. It'll be a heavy weight. 

Prompto begins to fidget on his lap, pulling Cor from his thoughts. Cor looks down, noticing he's dropped the teething ring. He leans down and picks it back up, trying to hand it to the child, but Prompto shoves at it with his small hand, clearly not interested. Cor sighs. "What do you want, then?" 

Prompto squirms, making to crawl off his lap, but Cor holds firm. "Prompto, my apartment's not safe for you." Cor doesn't think he understands, but the boy screws up his face anyway, letting out a frustrated wail. "No, don't start crying." 

It's too late, of course. More wails quickly follow the first, and it's not long before tears start sliding down his cheeks and snot streams from his nose, turning his face into a wet, disgusting mess. Cor groans, and starts bouncing the boy on his knee, trying to get him to calm down, but it does no good. 

Shutting his eyes as he feels a headache start to build, he can't help but wonder if Regis would let him sneak Prompto into Noctis' nursery for an hour. 

* * *

"Thank you," Cor says fervently, rubbing at the lingering pain in his forehead. "I didn't know what else to do with him." 

Regis gives him an amused glance. "There are very likely to be rumours. Noctis knows enough words to talk about him." 

Cor does know. Regis' kid is way too smart for his age. Still, he simply shrugs. "As long as Prompto isn't linked back to me, it's fine. And in a few days, it shouldn't matter."' 

"Have you found him a family yet?" 

"Potential." He watches as Prompto runs around Noctis' room happily, touching everything within reach—although maybe 'run' isn't the right word, as the poor kid spends more time tumbling to the floor and picking himself back up than he actually does running. "I've found three families that are interested." 

"You're meeting with them tomorrow?" 

"Two of them. And the last the next day." Noctis doesn't seem to know what to make of the new boy in his room. He stacks blocks in small towers, glancing up every so often to watch Prompto with a puzzled look on his face. It's kind of cute. For a moment, Cor entertains the thought of the two of them growing up together, Prompto spending his days playing with Noctis while Cor works, and then coming back home with Cor in the evenings. Resolutely, he shakes the thought off, ignoring the now familiar ache in his chest. It's an impossible daydream. 

"Do you intend to make them aware of his origins?" Regis asks, giving him a serious look as he shifts in his armchair. 

For a panicked moment, Cor thinks the king is talking about the barcode, and wonders how Regis can be so calm about it. Then he realises that Regis is talking about the fact that Prompto is from Niflheim—he'd deduced pretty easily that the kid is Sophia's, even though Cor hadn't confirmed it for him. He nods. "Yes, it's better they know." He tenses as Prompto suddenly bumps into one of Noctis' block towers, accidentally knocking it over. For a moment, Noctis is still, taking it in, and then he begins to cry noisily, frowning unhappily at Prompto through his tears. Confused, but not wanting to be left out, Prompto starts crying too. 

Cor groans, making Regis chuckle as he gets up and goes over to the children. He leans down to hug Noctis, reassuring the boy that it was just an accident and that Noctis can always build a new tower. After a hesitant moment, Cor gets up as well, going over to pick up Prompto and attempt to soothe the toddler. Thankfully Prompto is mollified pretty quickly, and is soon eager to get back to exploring. Cor lets him down, resuming his seat, and then watches as the king helps his son build a new tower, stacking the blocks in a fancier arrangement than the vertical tower Noctis had built. Noctis grins, delighted, and grabs a block to add to it. 

Cor's surprised to realise he feels a pang of jealousy, watching them. And perhaps a bit of longing. Regis is a natural at parenting, the way Cor suddenly yearns to be. Prompto toddles over to both of them then, and Cor tenses, not sure how Noctis will react, but the prince ignores the other boy, already at work making a new tower. Regis, however, smiles at Prompto, and holds out a block to him. Prompto smiles shyly, and then takes it, setting it carefully down on the floor. He plops down on the carpet and reaches out for another block that Regis subtly pushes towards him, and lays it beside the first one. 

"Does it not worry you?" Cor can't help but ask then, watching how kind the king is towards someone born in enemy territory. "That he's from Niflheim?" He'd been wondering ever since last night, when Regis had remarked on Prompto's resemblance to Sophia, and had then said not a word more about it. 

"It would be different if he was older now, and had been raised there, had been raised to think of us as enemy before he came to Insomnia," Regis answers, looking up at him. "But he's just a baby. He can't help the place of his birth." 

"You don't worry someone might come after him?" 

For a moment, Regis says nothing, his green eyes studying Cor intently, his head tilted slightly to the side. "Should I be?" he finally asks. 

Cor swallows, and silently hopes the king will forgive him if he ever finds out the secret Cor is keeping from him. "I don't know," he says, and that much at least is truthful. "It was just idle curiosity." 

"I can't see why Niflheim would be interested in one random child," Regis says, climbing to his feet. He heads back over to his armchair, taking a seat once more, managing to make the move look graceful in a way that only royalty can. 

"Nor I," Cor says honestly. MT or not, he can't see how one escaped baby would make a difference to them. And he wants Sophia's child to grow up having a happy life, not one of living in fear, constantly worrying he'll be snatched away back to Niflheim any moment. Whatever Sophia was running from, Cor hopes it ended with her. 

Shoving away the sorrow for his old friend, Cor watches her child play alongside the future king of Insomnia, and dearly hopes that he finds the right family to give Prompto the life he deserves.

**Notes for the Chapter:**

> Dammit Cor, fucking adopt Prompto already. One of these days I will write that AU, hopefully.


	3. The Third Day

**Notes for the Chapter:**

> Uh, so Prompto DLC borked my headcanon a little, buuuut I don't really care. This is just a little more AU now, haha.

The third day dawns dark and gloomy, rain pattering against the window in his bedroom, and Cor sighs as he wakes, finding the weather appropriate to his mood. He's meeting with two families today—the Bardus family and the Argentum family. He tries to convince himself that he's not dreading it, that he'll be relieved to put Prompto in good hands and get back to life as he'd known it before Sophia had stumbled back into it, but he can't lie to himself. He doesn't want to give up Prompto, no matter how much it's the right thing to do.

Groaning, he throws a hand over his eyes for a moment, trying to ignore the dull ache in his heart. When he feels like he can face the day, he drags himself out of bed wearily and stumbles off to the shower. The warmth of the water is soothing, and he indulges himself in it a little longer than usual. It's not as if he has work to worry about today, after all. Ten extra minutes in the shower won't hurt. 

When he finally leaves the bathroom, Prompto's awake in the playpen, wailing his head off. Cor rushes over to him, immediately picking him up and rocking him, trying to calm him. Prompto quiets down quickly, soon giving him a toothy grin. Cor can't help but to smile back at the child. "There, no need for tears, hmm, Prompto?" he says, and sets about seeing to the boy's breakfast. 

Half an hour later, Prompto's once again wearing more of his breakfast than he's eaten. Cor winces to look at the mess all over his face and clothes. He realises he probably needs to give Prompto a bath today before he meets with either of the families, but he's not sure how to go about it. He's never given a one year old a bath before. Surely, though, it can't be that difficult. Stick him in a tub with a bit of water and wash him, right? 

As it turns out, however, it _is_ that difficult. It only takes fifteen minutes before Cor is completely soaked, as is his bathroom floor, and the bathroom walls, and... really, there's water just about everywhere except on Prompto. The kid's been non-stop squirming, trying to get out of the tub and explore the new room, or delighting in smacking his hands repeatedly into the water that comes up to his stomach, laughing at the splashing that results. 

As hard as he tries though, Cor can't be mad at the boy. Prompto looks too damn adorable as he makes a wreck of Cor's bathroom, and the knowledge that he's going to be gone soon only softens Cor further. He snorts derisively at himself. What would the Crownsguard think, to see their stern and no-nonsense "Cor the Immortal" be completely undone by a one year old? It's almost a tempting enough thought to show up to the Citadel with Prompto in tow after all, in full view of the Crownsguard. He's detested that nickname ever since he was first given it ten years ago, and anything that gets people to stop calling him by it would be worth it. 

He sighs. As much as he wishes to keep Prompto, it's an idle fantasy, nothing more. He carefully rinses Prompto's hair one last time and then pulls the boy out of the tub, wrapping him up in a towel as he drains the water. Prompto pats at the towel, giggling happily and petting at the softness. Once he's gotten the toddler dry and stuck a new diaper on him, he begins the arduous task of dressing him. It's not any easier than yesterday, as Prompto continues to fling his limbs about, but at least nothing winds up inside out today. 

"What now, Prompto?" he asks when they're back in his living room, Prompto seated on his lap on the couch. "We've got some time before we meet with your potential new mom and dad." 

"Da!" Prompto cries, placing his hands against Cor's chest, giving him another toothy grin. 

For a moment, Cor forgets to take a breath, freezing in place as he stares down at the little boy in his lap. In his head he knows Prompto's only repeating the syllables he's hearing, learning them for the first time, but in his heart he's desperately wanting it to mean something more than that. He takes a breath and swallows hard, reaching up to gently rest his hand in the tangle of damp blond hair atop Prompto's head. "You'll have a dad soon, Prompto," he says quietly. "I promise you that." _I only wish it could be me._

* * *

It only takes two minutes for Cor to realise that there's no way he can give Prompto to the Bardus family. 

He knows he can't let his attachment to the toddler cloud his feelings, so he tries very hard not to judge when he first sees their place. The outside is shabby looking, but given the neighbourhood in which the house is located, he's expected that. The inside, however, is a different story entirely. The smell is the first thing he notices when he steps inside—it's strong, cloying, a mixture of mold and garbage and rotting food that makes Cor's stomach roll as he tries not to visibly gag. There's trash piled up in the living room that's ankle-deep, and he clutches Prompto tighter to him as he tries very hard not to look at the bugs he spies crawling along the walls. 

"Please, come in, have a seat," Mrs. Bardus says, gesturing to a worn-looking couch. It's free of the junk that clutters the rest of the room, but the fabric is covered in all manner of crumbs and stains that make Cor cringe to look at. "My husband will be along shortly. He had to stay late today." 

Cor nods, and picks his way over to the couch, gingerly sitting on the edge of a cushion, Prompto held firmly in his lap. She perches herself on some boxes across from him, the centre of them dipping under her weight. He studies her, not encouraged by what he sees. Her eyes are lined with dark circles under them, her makeup is visibly smudged, her dark hair is pulled back in a messy, greasy ponytail that's falling apart, her clothes are torn and dingy in places... she doesn't seem capable of taking care of herself, much less a one year old boy. "What does your husband do?" he asks politely, though he's already discretely had their files pulled. They're both teachers, which is why he chose to interview them first—he assumed their jobs would give them plenty of experience to be parents. Now he's second-guessing that. 

"Oh, he teaches first year of high school. I teach first grade. We're around children a lot." 

"It must be very fulfilling," he says inanely. 

"It's a paycheck," she replies, and he makes a polite noise to indicate he's heard. 

They sit in awkward silence for a few minutes, and he keeps waiting, expecting her to ask about Prompto, who is wriggling around curiously around in his lap, but she says nothing about the boy at all. It solidifies his decision to not give Prompto to this family, and he can't figure out why in the world they're interested in him. He's tempted to just go ahead and leave, but it feels too rude. Still, the sooner he can make a polite excuse and leave, he intends to. 

The sound of a key in the lock draws him from his thoughts, and then a man is stepping through the front door into the room. Cor looks him over immediately, assessing him. He's dressed in slacks and a button up with a tie, all of his clothes neatly pressed and absent of any tears or stains. His brown hair is nicely combed back, and looks recently washed, unlike his wife's. He's more or less clean-shaven, just a hint of a five 'o clock shadow. He smiles broadly when he spots Cor and Prompto, making a beeline for them. "Hi there! I'm Robert, and you must be Cor." He reaches out a hand to tousle Prompto's hair, and Cor has to resist the urge to yank him out of the man's reach. "This must be the little guy! What's his name?" 

"Prompto," Cor says quietly. He's starting to get a better picture of what's going on here. Only one of them wants a child here, and it's not the woman sitting across from him with a pinched, displeased look on her face while her husband fusses over a toddler. And if Robert lived alone, in a house that was as clean as his person, Cor would be a lot more willing to consider giving Prompto to him. But he can't let Prompto go to someone who isn't going to love him, who's going to keep him in filth and neglect. 

"Prompto... he looks so sweet," Robert says, smiling down at the boy as he tickles under his arms. Prompto giggles, squirming. 

"He is." 

"Robert," Mrs. Bardus says sharply, and her husband's hand drops, his face falling. He takes a seat at the opposite end of the couch, looking down at the floor. There's more awkward silence, and Cor desperately wishes his phone would ring and give him a reason to leave. 

"Where's his family?" Mrs. Bardus asks abruptly. 

"Ah... they passed away," Cor says. "A car accident." There's no point in telling them the truth when they're not going to keep the child. It's too much of a risk. 

"He looks like those filthy Nifs," she mutters, glancing briefly at him. 

"Caroline," Robert says, mortification clear in his voice. "He's just a little boy." 

"He's Lucian," Cor says through clenched teeth, wrapping his arms tighter around Prompto, instinctively trying to shield him from the woman's hurtful words. And it's not entirely a lie. Prompto may have come from Niflheim, but he's going to be raised here in Lucis, by a Lucian family—he'll be as Lucian as anyone else in Insomnia. 

Caroline opens her mouth to say something else—no doubt cruel and discriminating—but miraculously, Cor's phone does ring then. Clearly the Astrals have heard him and granted him his wish. He pulls it from his pocket and glances down at the display. He doesn't recognise the number, but it doesn't matter. "I'm sorry," he says, standing and shifting Prompto against his hip. "I must get this. I have your number, I'll call you." 

"Of course," Robert says politely, seeing him to the door. He steps out after Cor, shutting the door behind them. "I'm sorry about Caroline," he says when they're on the porch. "She watched her younger sister get killed by Niflheim soldiers when they were children. Anything that reminds her of it is hard." 

"I'm sorry to hear that," Cor says, though he isn't at all. 

"I know you won't give him to us," Robert sighs. "And I can understand. I would do the same in your place. I hope you can find someone suitable for him. He deserves two parents that are going to love him." 

"Thank you," Cor says, blinking, not expecting such kind words. "I hope I do too." 

* * *

The meeting with the Argentums an hour and a half later goes much better. Their house is worn but clean and well-cared for, and Mrs. Argentum's halfway down the walk squealing about what a cute baby Prompto is almost as soon as Cor gets him out of the car. They both ask him many questions about Prompto, and Cor answers every one of them honestly with an ache in his heart. Everything he's seeing and hearing says that the Argentums will be a great fit for Prompto, to the point where he doesn't think he'll need to meet with the last family tomorrow. 

He should be thrilled by this fact, but all he wants to do is hide away in his apartment and cry the way he hasn't since he was a small child. 

They ask him more questions, and in turn tell him about their own fruitless struggles to have a child, and how they'd despaired of ever having one. 

"We looked into adoption a few months ago," Mr. Argentum says. "But they expect an exorbitant amount of crown sterlings up front just for a chance to adopt, and we can't afford that." 

"Even if we could, it might be years before we could be given a child. And we were worried about being too old by the time we were allowed to adopt," Mrs. Argentum added, twisting her hands anxiously. 

"We want to be able to devote plenty of our time and energy to a child. You understand? We don't want to be in our thirties trying to find time to play with an energetic toddler." 

"Of course," Cor murmurs to them. "That's understandable." He listens as they talk about all of their hopes for a child, all the things they plan on doing if he gives them Prompto, and there's nothing in their words that suggests they would be terrible parents. He hates it. 

"There's something you need to know about him," he says at one point, using the intimidating voice he puts on for the Crownsguard. 

They both nod at him, looking curious, but nothing more. He inwardly sighs, pulling back the tiny wristband he'd put on Prompto after his bath, revealing the barcode to them. Mrs. Argentum furrows her brows, looking at it for a moment before glancing to Cor uncertainly. "A tattoo?" 

Cor shakes his head. "He's from Niflheim. His mother managed to escape with him and flee back to Lucis a few days ago. She was from Lucis originally, and we were childhood friends, so she brought him to me. I don't have any confirmation yet, but I suspect the Niflheim army planned to raise him up into a mindless soldier, and branded him with this barcode." 

"Oh, how horrible!" Mrs. Argentum gasps, covering her mouth with her hand. 

Mr. Argentum shakes his head solemnly. "Poor little guy," he says. "No child deserves that." 

Cor feels his stomach clench at their reactions. They're the right responses, the kind he's looking for, so why does it hurt so much to hear them? "No one can know about it," he says firmly, looking hard at both of them to make sure they understand. " _No one_ , do you understand? We don't know enough about Niflheim or their intentions yet, and having unsubstantiated rumours flying around will only do more harm than good, and I fear the treatment Prompto would get if people came to know the truth of his origins." 

"We understand," Mr. Argentum says immediately. "We can make sure he always keeps it covered." 

"It's not a problem. It doesn't matter to us where he comes from. He can't help the circumstances of his birth." 

They talk a while longer, until Prompto gets restless with all the boring grown up talk and being confined to his lap, and starts fussing noisily. Cor starts to bounce him automatically, but Mrs. Argentum gets up, holding her arms out. "May I?" Cor swallows down the response he wants to say, and hands Prompto to her, watching with a heavy heart as she soothes him, smiling gently at him. There's nothing awkward in her motions, and he feels a twinge of jealousy at how natural it seems for her, as if she's meant to be his mother. 

He doesn't want to give Prompto up. He _doesn't_. 

But Prompto deserves someone better than him, so he has no choice. He forces back the empty ache he feels, and makes arrangements for the Argentums to take Prompto—along with all the stuff Cor's bought him—tomorrow. He knows if he tries to wait any longer, he won't come back. 

He takes his leave quickly after that, and soon enough he and Prompto are back in his apartment, cuddled up together on his couch. He's put the television on for Prompto, some brightly coloured cartoon with a lot of singing that keeps the boy enraptured. Cor watches Prompto clap his hands together in delight, and a fond smile briefly lights up his face before fading. This is the last night he's going to have with Prompto. The idea hurts. 

For a moment, he viciously wishes that Sophia had died before she ever made it back to Insomnia, that she hadn't brought Prompto to him. He's only known the boy for three days, really, but it feels like so much longer than that. It feels stupid to think it, but he already feels such a close bond with this child, and he knows he's going to lose a part of himself when he loses Prompto. His chest aches painfully at the thought, his throat tightening in grief. He hugs Prompto to him, closing his eyes so that he doesn't give in to the tears he feels threatening. The combined scent of baby shampoo and baby powder he'd used on Prompto wafts up to him, and he breathes it in, knowing he'll never have a chance to again. 

"It's the right thing, Prompto," he murmurs. "You need a real family, two parents that will be able to care for you the way I can't. You need people that aren't married to their job, and that can give you the life you deserve." 

Prompto tips his head back, looking up at him with a bright smile on his face. "Da!" he says, giggling, and Cor finally loses the battle with his tears. It's a short cry, and a silent one, but when he's done he feels as exhausted as he would after crying for hours. He scrubs at his face wearily, then pulls out his phone, bringing up the camera app and switching it to the front-facing camera. He stretches his arm out, angling the phone to fit both himself and Prompto into the frame, and snaps the picture. 

"I can't be your dad, Prompto," he tells the child, pressing a gentle kiss to the top of his head. "But I promise I won't ever forget you."

**Notes for the Chapter:**

> Baawww I made myself sad. Whoops. If no one's noticed, I've been loosely sticking to the rule of three for these fics so far, so this is the last chapter for "Lack of Instinct." There may or may not be more fic for the headcanon though, set much later on.
> 
> Buuuut if anyone from months ago is still sticking around, I have _finally_ started writing out some tentative notes for the Dad!Cor AU I wanna do, like... working out how to do it, and getting ideas finally. So there's a higher chance I'll eventually write it and post it, yeah \o/
> 
> Btw, how do people feel about Cor/Regis? Does fandom have an opinion? I haven't seen much of it.


End file.
